The ecto-enzyme CD38 is a marker of unfavorable prognosis for chronic lymphocytic leukemia (CLL) patients and an indicator of activation and proliferation of leukemic cells. Here we show that CD38 is enzymatically active in primary CLL cells and that its forced expression increases disease aggressiveness in a xenograft model. The effect is completely lost when using an enzyme deficient version of CD38 with a single amino-acid mutation. Through the enzymatic conversion of NAD, CD38 increases cytoplasmic Ca2+ concentrations, positively influencing proliferation, chemotaxis, adhesion and matrix digestion. Inhibition of the enzymatic activities of CD38 using the flavonoid kuromanin blocks CLL homing. In a short-term xenograft model using primary cells, kuromanin treatment traps CLL cells in the blood, increasing responses to chemotherapy.
The enzymatic activities of CD38 enhance CLL growth and trafficking: implications for therapeutic targeting.
No sample metadata fields
View SamplesGoblet cell metaplasia and mucus hypersecretion are disabling hallmarks of chronic lung diseases for which no curative treatments are available. Therapies targeting specific upstream drivers of asthma have had variable results. We hypothesized that an a priori-knowledge independent approach would point to new therapies for airway goblet cell metaplasia. We analyzed the transcriptome of an organotypic model of human goblet cell metaplasia. We combined our data with previously published datasets from IL13-exposed in vitro and asthmatic in vivo human airway epithelial cells. The drug perturbation-response connectivity approach identified the heat shock protein 90 (HSP90) inhibitor geldanamycin as a candidate for reverting airway goblet cell metaplasia. We found that geldanamycin not only prevented but reverted IL13-induced goblet cell metaplasia. Geldanamycin did not induce goblet cell death, did not solely block mucin synthesis, and did not block IL13 receptor-proximal signaling. Moreover, the transcriptional effects of geldanamycin were absent in unstimulated cells and became evident only after stimulation with IL13. The predicted mechanism of action suggested that geldanamycin should also revert IL17-induced goblet cell metaplasia, a prediction confirmed by our data. Our findings suggest HSP90 activity may be required for persistence of goblet cell metaplasia driven by various mechanisms in chronic lung diseases. Overall design: For both batches, airway epithelia cultures from the lungs of eight different humans were studied, therefore, there are eight biological replicates. Comparisons should be made within batches. In batch 1 (XAM1), epithelia were exposed to vehicle (DMSO 0.5%), geldanamycin 25 uM, or the HDAC6 inhibitor ISOX 10 uM for 48 hours. In batch 2 (XAM3), the epithelia were exposed to vehicle (DMSO 0.5%), IL13 (20 ng/mL) or IL13 plus geldanamycin (10 uM) for 48 hours.
HSP90 inhibitor geldanamycin reverts IL-13- and IL-17-induced airway goblet cell metaplasia.
Specimen part, Treatment, Subject
View SamplesAnalysis of human glioblastoma multiforme tumors revealed genes that are upregulated in tumors expressing EGFRvIII compared to those expressing wild-type EGFR
Sprouty2 Drives Drug Resistance and Proliferation in Glioblastoma.
Specimen part
View SamplesAnalysis of rat tumor xenografts revealed genes that are upregulated in tumors expressing EGFRvIII
Sprouty2 Drives Drug Resistance and Proliferation in Glioblastoma.
Sex
View SamplesUbiquitination is a post-translational mechanism of control of diverse cellular processes. We focus here on the ubiquitin ligase Fbw7, a recently identified hematopoietic tumor suppressor that can target for degradation several important oncogenes including Notch1, c-Myc and cyclin E. We have generated conditional Fbw7 knock-out animals and inactivated the gene in hematopoietic stem cells (HSC) and their differentiated progeny. Deletion of Fbw7 specifically and rapidly affects the HSC compartment in a cell-autonomous manner. Fbw7-/- HSCs show defective maintenance of quiescence, leading to impaired self-renewal and a severe loss of competitive repopulating capacity. Furthermore, Fbw7-/- HSC are unable to colonize the thymus leading to a profound depletion of T cell progenitors. Deletion of Fbw7 in bone marrow stem cells and progenitors leads to the stabilization of c-Myc, a transcription factor previously implicated in HSC self-renewal. On the other hand, neither Notch1 nor cyclin E are stabilized in the bone marrow of Fbw7 deficient mice. Genome-wide transcriptome studies of Fbw7-/- HSC and hematopoietic progenitors indicate that Fbw7 controls, through the regulation of HSC cell cycle entry, the global transcriptional signature that is associated with the quiescent, self-renewing HSC phenotype.
Control of hematopoietic stem cell quiescence by the E3 ubiquitin ligase Fbw7.
No sample metadata fields
View SamplesGene expression analysis of purified KitL-tomato+ and KitL-tomato- thymic vascular endothelial cells, cortical and medullary thymic epithelial cells from 5 weeks old male kitL-tomato reporter mice Overall design: Differentially expressed genes analysis of thymic stromal cells
A dynamic niche provides Kit ligand in a stage-specific manner to the earliest thymocyte progenitors.
No sample metadata fields
View SamplesThe transcriptional profile of the human multiple myeloma (MM) cell line MM.1S treated with MLN4924 vs control MM.1S cells was characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip, according to previously described protocols for total RNA extraction and purification; cDNA synthesis; in vitro transcription reaction for production of biotin-labeled cRNA; hybridization of cRNA with U133plus2.0 Affymetrix gene chips; and scanning of image output files. Scanned image output files were analyzed using DNA-Chip Analyzer (dChip) (www.dchip.org), including conversion to DCP files, normalization and modeling. The gene expression profile of MM.1S cells for each time point of MLN4924 treatment was compared to the profile of control MM.1S cells.
Molecular and cellular effects of NEDD8-activating enzyme inhibition in myeloma.
Cell line, Time
View SamplesThe Hedgehog (Hh) signaling pathway is a developmentally conserved regulator of stem cell function. Several reports suggested that Hh signaling is an important regulator of hematopoietic stem cell (HSC) maintenance and differentiation. Here we test this hypothesis in vivo using both gain- and loss-of-function Hh genetic models. Surprisingly, our studies demonstrate that conditional Smoothened (Smo) deletion or over-activation has no significant effects on adult HSC self-renewal and function. Moreover, they indicate a lack of synergism between the Notch and Hh pathways in HSC function, as RBPJ- and Smo-deficiency do not affect hematopoiesis. In agreement with this notion, detailed genome-wide transcriptome analysis reveals that silencing of Hh signaling does not significantly alter the HSC-specific gene expression signature. Our studies demonstrate that the Hh signaling pathway is dispensable for adult HSC function and suggest that the Hh pathway can be targeted in future clinical trials addressing the effect of Hh inhibition on leukemia-initiating cell maintenance.
Hedgehog signaling is dispensable for adult hematopoietic stem cell function.
Sex
View SamplesRecurrent mutations in RNA splicing factors SF3B1, U2AF1, and SRSF2 have been reported in hematologic cancers including myelodysplastic syndromes (MDS) and chronic lymphocytic leukemia (CLL). However, SF3B1 is the only splicing associated gene to be found mutated in CLL and has been shown to induce aberrant splicing. To investigate if any other genomic aberration caused similar transcriptome changes, we clustered RNASeq samples based on an alternative 3' splice site (ss) pattern previously identified in SF3B1-mutant CLL patients. Out of 215 samples, we identified 37 (17%) with alternative 3' ss usage, the majority of which harbored known SF3B1 hotspot mutations. Interestingly, 3 patient samples carried previously unreported in-frame deletions in SF3B1 around K700, the most frequent mutation hotspot. To study the functional effects of these deletions, we used various minigenes demonstrating that recognition of canonical 3' ss and alternative branchsite are required for aberrant splicing, as observed for SF3B1 p.K700E. The common mechanism of action of these deletions and substitutions result in similar sensitivity of primary cells towards splicing inhibitor E7107. Altogether, these data demonstrate that novel SF3B1 in-frame deletion events identified in CLL result in aberrant splicing, a common biomarker in spliceosome-mutant cancers. Overall design: 13 CLL samples, 5 SF3B1 WT, 5 SF3B1 p.K700E, and 3 with in-frame deletions around the K700 position of SF3B1
Novel <i>SF3B1</i> in-frame deletions result in aberrant RNA splicing in CLL patients.
Disease, Disease stage, Subject
View SamplesSchwann cell remyelination defects impair functional restoration after nerve damage, contributing to peripheral neuropathies. The mechanisms that mediate remyelination block remain elusive. Upon small-molecule epigenetic screening, we identified HDAC3, a histone-modifying enzyme, as a potent inhibitor of peripheral myelinogenesis. Inhibition of HDAC3 markedly enhances myelin growth and regeneration, and improves functional recovery after peripheral nerve injury. HDAC3 antagonizes myelinogenic neuregulin/PI3K/AKT signaling axis. Moreover, genome-wide profiling analyses reveal that HDAC3 represses pro-myelinating programs through epigenetic silencing, while coordinating with p300 histone acetyltransferase to activate myelination-inhibitory programs that include HIPPO signaling effector TEAD4 to inhibit myelin growth. Schwann-cell-specific deletion of either Hdac3 or Tead4 results in a profound increase in myelin thickness in sciatic nerves. Thus, our findings identify the HDAC3-TEAD4 network as a dual-function switch of cell-intrinsic inhibitory machinery that counters myelinogenic signals and maintains peripheral myelin homeostasis, highlighting the therapeutic potential of transient HDAC3 inhibition for improving peripheral myelin repair. Overall design: 4 RNA-Seq samples from P6 sciatic nerves of Ctrl and Hdac3-cKO mice (Cnpcre-Ctrl, Cnpcre-cKO, Dhhcre-Ctrl, Dhhcre-cKO)
A histone deacetylase 3-dependent pathway delimits peripheral myelin growth and functional regeneration.
Specimen part, Subject
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